Collapsible shafts



Aug. 7, 1962 R. P. WILLARD coLLAPsIBLE sHAFTs Filed Feb. 4, 1960 INVENTOR Y WM.,

ATTORNEYS @wf www l l \\N N .-7 /1 4 A www f rates nite This invention relates to rotary shaft -assemblies which may be expanded and collapsed for use in axially supporting loads such as rolls of paper or fabric, especially in connection with winding or unwinding the material comprising such rolls.

Sometimes the paper or other material is Wound directly on the shaft, but perhaps more frequently the roll is formed upon a core element into which the shaft may be slid longitudinally while in contracted or collapsed condition. However, in either case the rolls are often quite wide and sometimes the weights to be sustained by the 'shafts are enormous as when the material to be supported 1s newsprint.

Under these conditions, it is not unusual for the axial bore through the roll to be somewhat warped out of true cylindrical configuration; rbut as a more likely occurrence, in the case of continuous elongated engaging elements in the shaft assembly, these elements themselves can become bent or warped out of accurate longitudinal alignment. Thus, the engagement of the shaft parts with the internal surface of the core can be uneven and unbalanced in the transmission of torque between the shaft and the roll, and quite a small deection of elongated engaged strips or leaves can result in fatigue failure through constant reversal of stress during rotation for winding or un- Winding.

The principal object of the present invention is to provide a novel and improved collapsible shaft which is relatively simple and easy -to yconstruct and operate, and which is qualified to obviate or minimize the diihculties experienced with earlier proposals.

In its preferred embodiment, the invention contemplates the provision of a collapsible shaft comprising a cylindrical shell of sufliciently sturdy construction to sustain the shear and bending stresses of the load to be supported, this shell being provided with slots or openings at intervals about its periphery through which project elements which are adapted to press ydirectly against the the inner surface of the core of the roll. These openings are of relatively short dimension lengthwise of the shaft and are preferably arranged in staggered groupings angularly about the cylindrical `shaft wall. The par-ticular novel arrangement of pressure elements contributes greatly to the effectiveness of the shaft assembly, as will -be described in detail as the specification proceeds.

Other points of novelty include ingenious and effective means for expanding the shaft assembly by means of fluid pressure, and novel and improved resilient means for continually urging the projecting core engaging parts toward retracted positions against the pressure of the fluid.

In the embodiment of the invention illustrated and described herein, the external load contacting elements comprise blades or plates set edgewise and positioned radially of the shaft, and are secured to inner segmental motor or actuating plates of lengths to accommodate several of the projecting contact elements along a fraction of the length of the entire shaft.

Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which certain embodiments of the invention are illustrated by way of example.

In the drawings:

3,048,345 Patented Aug. 7, 1962 FIGURE l is a View in perspective of a collapsible shaft embodying the principles of the invention;

FIGURE 2 is a longitudinal sectional View through the axis of the shaft shown in FIGURE l, the shaft being in expanded condition;

FIGURE 3 is a transverse sectional view taken on line 3 3 of FIGURE 2;

FIGURE 4 is a similar view showing the shaft in collapsed or retracted condition;

FIGURE 5 is a fragmentary longitudinal sectional view on an enlarged scale showing in better detail one of the return spring installations of this embodiment; and

FIGURE 6 is a fragmentary transverse sectional view taken on line 6 6 of FIGURE 5.

In the drawings, there is illustrated an embodiment of the invention in which groups of gripping lugs are distributed upon a roll supporting shaft, urged toward the core of the shaft for gripping purposes and normally urgedV toward the axis of the shaft for retraction, and projected outwardly toward gripping position by pneumatic means. A shaft ytypical of this embodiment of the invention is given the general reference numeral 21u and comprises the continuous elongated hollow cylindrical body member 220 which is sleeved at its ends over the stub shaft or trunnion portions of the device designated 213 and 214.

The tubular member 225 is provided with multiple series of aligned slots, Ithese series of slots being arranged in discontinuous groups staggered with respect to each other along the length of the shaft 210. These slots are indicated at 215 in the end series and at 216 in the intermediate series of openings. lDisposed for projection through these slots lare the narrow plate-like lugs 225, the lugs of each aligned series being secured as by means of the pins or rivets 226 with the internal discontinuous supporting leaf members 22'7.

As clearly shown in FIGURES 3 and 4 of the drawings the supporting leaves 227 are arcuate in form, conforming approximately rto the curvature of the inner surface of the tubular shaft element 221i. The groups of lugs 225 are preferably four in number in each series and spaced apart through an angle of around the periphery of the shaft, lbut a fewer number may be selected for some purposes. However, the different series of lugs lengthwise of the shaft are staggered one with respect to lthe other as clearly shown in FIGURE l of the `drawings where, 4for example, the end series consists of three lugs in each group and the intermediate series groups consist of four aligned lugs. In this particular embodiment the angle of offset between the staggered `series of lugs is 45. The staggering of the series of lugs is for the same purpose as explained in my co-pending application Serial No. 6,673, filed of even date herewith, especially in connection with lFIGURES 8 and 9 of the drawings of that application.

It will be noted that the inner supporting leaf members 227 are longitudinally grooved as at 229 for two reasons. Frist, in order to more accurately and rigidly receive the lugs 225 and, second, for the purpose of providing pockets for the reception of the leaf springs 230 which extend along portions of the inner wall of the tubular member 22) between the openings 215 and 216 through which the lugs 225 extend. Clusters of two or more leaf springs 230 may be employed, if desired, there being shown three in the enlarged views of FIGURES 5 and 6, A guide pin 231 may be used to fix the location of the spring elements 230. In these gures the arrangement is shown in expanded position where the lugs are in engagement with the rolls to be supported by the shaft, but it will be readily understood how the springs 230 urge the -supporting leaves 227 radially inwardly so that the lugs 225 are retracted within the openings 215, 216 of the tubular member 220 as clearly shown in FIGURE 4 of the drawings.

A similar inflatable bag arrangement is employed in this embodiment of the invention for projecting the lugs into gripping relationship with the rolls, and this arrangement includes the bag 235 which is of tubular configuration, the left-hand end as viewed in FIGURE 11 being received within a socket 21311 in the trunnion member 213 and surrounding the cylindrical portion of the plug 23S. This plug has a conical portion 239 which is preferably provided with circular serrations and is surmounted by a threaded stem 240 about which the nut 243 is threaded. A conical lsleeve 242 surrounds the inward portion of the stem 240 and is provided with a serrated outer surface of opposite taper to the tapered portion 239 of the plug 238. An enveloping sleeve or binding collar 245 having oppositely tapered conical inner surfaces surrounds the narrowed end of the bag 235 and serves to bind the bag against the serrated portions of the parts 239 and 242 when the nut 243 is screwed down. A washer 246 may be interposed between the nut and the element 242.

At the right-hand end of the shaft as seen in FIGURE f 2, the trunnion member 214 is provided with a socket 214A within which an end of the bag 235 is disposed. A plug 250 has its cylindrical portion disposed Within the end ofthe -bag and is provided with a serrated tapered portion 251 and a threaded stern portion 252. A tapered conical sleeve 262 is fitted onto the stem 252 and this sleeve has an outer serrated portion similar to that of the portion 251 of the plug. Surrounding the narrowed end of the Ibag 235 and serving to compress it against the oppositely sloping serrated portions mentioned, is the sleeve 263 which has a double tapered internal surface conforming generally to the opposite inclinations of the inner serrated elements. A nut 264 is threaded on the stem 252 and a washer 265 may be interposed between the nut and the element 262.

A tube 257 extends through the trunnion member 214 and may be an integral extension of the threaded part 252 of the plug 250 or may be a separate stem threaded into such plug. The outer end of the tube 257 is provided with a valved coupling 260 for the admission of compressed air.

It will be readily seen how the inflation of the bag 235 will cause the inner supporting leaves 227 to move radially outwardly from the idle position shown in FIGURE 3 to the position shown in FIGURE 4, whereupon the clamping lugs 225 are projected through the openings and into gripping contact with the core of the roll supported upon the shaft.

Various changes and modifications may be made in the embodiments illustrated and described herein without departing from the scope of the invention as defined `by the following claim.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

A collapsible shaft assembly of the class described and as particularly adapted for the rotatable support of heavy rolls of newsprint or similar cored loads, said assembly comprising, in combination, a. tubular cylindrical body member having gudgeons at each end for mounting the shaft assembly for rotation, a plurality of circumferentially spaced rigid oating leaf elements extending generally longitudinally within said body member and arranged for radial bodily movement toward the inner surface of the wall of said body member, a series of longitudinally spaced and aligned slits in said wall adjacent the position of each of said leaf elements, a series of lugs associated with each of said leaf elements, each lug disposed n one of said slits and movable radially therein to project therefrom and to be retracted from a projected position, a slot formed in the outward surface of each of said leaf elements facing said series of slits and extending the full length of said element, the radially inner ends of the lugs of each series 4being seated in the slot of one of the leaf elements and secured therein, and at least one pre-stressed bent leaf spring seated in portions of each of said slots not occupied by said lugs, Said spring being compressed between the bottom of said slot and the adjacent unbroken inner surface of the wall of said body member, and uid pressure means for urging said leaf elements and said attached lugs outwardly of the axis of said body member to project said lugs through said slits against the urging of said springs; the several series of slits in the wall of the body member, and the leaf elements with their series of lugs all being multiplied throughout the length of the shaft assembly and arranged in separate circumferential groups, said groups comprising two end groups and an intermediately disposed group, the leaf elements and Series of slits and lugs of adjacent groups being displaced augularly from each other about the periphery of said body member.

References Cited in the file of this patent UNITED STATES PATENTS 2,059,040 Scholtes Oct. 27, 1936 2,215,069 Meisel Sept. 17, 1940 2,331,743 Sullivan Oct, 12, 1943 2,537,492 Tidland Jan. 9, 1951 2,558,689 Miller June 26, 1956 FOREIGN PATENTS 866,907 Germany Feb. 12, 1953 

